The subject matter disclosed herein relates generally to salt purification and, more particularly, a system for removing a high purity salt from a brine.
There are several regions in the United States (e.g., the southwestern United States including New Mexico, Southern California, and parts of Texas) and throughout the world that experience shortages in potable water supplies due, in part, to the arid climate of these geographic locales. As water supplies are limited, the need for innovative technologies and alternative water supplies is important. One method for obtaining an alternative source of potable water uses desalination systems to produce the potable water.
The desalination process may involve the removal of salts from seawater, agricultural run-off water, and/or brackish ground water brines to produce potable water. Desalination may use an assortment of filtration methods, such as nanofiltration and reverse osmosis, to separate the raw stream into a desalinated water stream and a tailing stream. The tailing streams may contain various salts and other materials left over after the desalination process. Indeed, disposal of the tailing streams produced by desalination may result in soil degradation and ground water contamination. Thus, alternative and innovative uses of the tailing streams may reduce undesirable results of disposing the tailing streams.
One such alternative use may involve processing the tailing stream to remove valuable salts and other minerals. In particular, inland brackish water and seawater may be rich in sodium chloride, sulfates, magnesium, calcium, and other minerals. Membrane-based desalination systems may employ a combination of nanofiltration and reverse osmosis to facilitate the desalination and removal process. Following an initial separation of a desalinated water stream from a tailing stream, the tailing stream may be processed by a mineral and/or salt removal system. However, salt purification in membrane-based systems may result in a salt with a high number of impurities, such as calcium, magnesium, and bromide. Existing methods for removal of impurities may be inefficient and/or expensive.